Gas-engine



No. 6|0,034. Patented Aug. 30, I898.

A. H. DINGMAN,

GAS ENGINE.

(Application filed. June 25, 1897.) (No Model.)

3 Sheds-Sheet l.

No. 6I0,034. Patented Aug. 30, I898.

A. H. D INGMAN.

GAS ENGINE.

(Application filed June 25, 1897.)

(No Model.) 3 Sheets-Sheet 2.

THE NORRIS PETERS ca. P'NOTQLXTHOH wAsmumcM, n. c

No. 610,034. Patented Aug. 30, I898.

A. H. DINGMAN.

GAS ENGINE. (Application filed June 25, 1897.)

3 Sheets-Sheet 3.

(No Model.)

UN 1TB ATES;

FETCH.

YA-TENT ALLEN II. DINGMAN, OF DE HAVEN, PENNSYLVANIA, ASSIGNOR OF ONE- IIALF TO JAMESAMM, OF BUFFAL Q'NEW YORK.

GAS-ENGINE.-

srnolrrch'rron' swa part of Letters Patent No. 610,034, dated August so,1898.

Ap fi ti fl d l'une 25,1897. Serial No. 642,291. at, model.)

To all whom it may concern:

Be it known that I, ALLEN II. DINQMAN, a citizen of the United States,residing'at De Haven, in the county of Allegheny and State" ofPennsylvania, have invented new and useful Improvements in Gas-Engines,of which the following is a specification.

This invention relates to gas-engines, and

has for its objects the various improvements in construction andcombination of engine parts as hereinafter described. The engine is moreparticularly designed to be operated by the explosion of natural orartificially-prepared combustible gas or gases in combination withatmospheric air; but it may be also wholly or partly operated by steam.

One of the principal purposes of my invention is to provide for theaccumulation of gas at a very high pressure by operation of the engine,the accumulated gas to be used for driving other engines or for theoperation of pumps or various machinery and for other purposes, eitheralone or in connection with steam plants.

a In the annexed drawings, illustrating the invention, Figure 1 is aplan of my improved gas-engine in part horizontal section. Fig. 2 is aside elevation of the same, partly in section. Fig. 3 is a.cross-sectional detail view on the line 3 3 of Fig. 2, showing theenginecylinders and one of the port cut-oft valves. Fig. 4 is asectionalelevation illustrating the packing for the portcut-olf valves.Figs. 5 and 5 are sectional views of the igniter or combustion-jet.Figs. 6 and 6 show the double air-valve in longitudinal section and top.View, respectively. Fig. 7 is a view of the positive reverse-gear. Fig.8 is a sectional view of a packing-box for a piston-rod or valvestem.Fig. 9 is a cross-section on the line 9 9, of Fig. 2 through theengine-cylinders, vapo rizer, and gas-accumulator. Figs. 10 and 10 areviews of the main engine-valve. Fig. 11

is a sectional view of a cross-head connection.

Referring to Figs. 1 and 2 ofthc drawings, the numeral 1 designates thebed-plate or base portion of the engine-frame, which may be supportedonan engine-block 2, as shown; At the forward end of the engine-frame ismounted the crank-shaft 3, that carries at one end the balance-wheel 4and at the other end a pulley or band-wheel 5 for attachment .of belting6 to transmit power. As shown in Figs. 1 and 2, the crank-shaft 3 ismounted in journal-boxes having hinged caps or covers 7, which keep theshaft in better line and are stronger, more durable, have fewer bolts,and are more easily and conveniently ad- 1 tion of the en gine-frame.

There is connected with the engine-shaft 3 another crank 17 which may becast integral with the balance-Wheel 4, as shown. To a wrist on thiscrank 17 is attached one endot a connecting-rod 18, Figsfl and 2, theother end of which connects with a sliding crosshead 19, to which issecured the piston-rod 20 of a piston 21, working in a combustioncylinder or chamber 22, that is supported parallel with the mainengine-cylinder.

For each sliding cross-head l3 and 19 there is provided on theengine-frame a cylindrical guide 23, conforming to the preferablycylindrical shape of the cross-head therein. Each cross-head 13 and 19is recessed at one end, as shown. In this recessed portion of eachcross-head is situated a wrist-pin 12, that is preferably cast integralwith the cross-head andmade polygonal or hexagonal in crosssection, asshown in Fig.11. The brasses 11 have polygonal inner faces conforming tothe shape of the wrist-pin 12, and their outer surfaces are curved toconform to the end ofthe connecting-rod and its strap. This strap 10 issecured to the connecting-rod by meansof a bolt and nut 24:, a key 25and gib 26 being provided to take up wear in the cross -headconnections, and a set-screw 27 is mounted in the gib to hold the key inposition. The manner of attaching a connecting-rod to the wristpin 12,Fig. 11, is the same for both cross-heads 13 and 19, andsimilarconnections may be provided for attachment of the respectiveconnecting-rods 9 and 18 to the crank-wrists of the engine shaft. As thebrasses 11 do not move on the wrist-pins 12 there can be no wear betweenthem. The wear that comes between the brasses, connecting-rods, andstraps is easily taken up by adjustment of the fastenings, and when thebrasses are worn out they can be readily replaced with new ones thatwill always fit the wrist-pins, the brasses being made convenientlyinterchangeable, and thus the cross-heads will not have to be changed toget a new pin. The cylindrical form of the cross heads 13 19 and guides23 greatly reduces the lost motion from wear and provides for a verysteady movement. The provision of the two cylinders 16 and 22,with theirpistons connected to the two cranks 8 and 17 set in different planes,obviates a deadcenter.

Between the two engine-cylinders 16 and 22 there is a preferablycylindrical valve-chamber 28, provided with suitable ports, ashereinafter explained. In this valve-chamber 28 there is a slide-valve29, provided with a stem 30, for which there may be arranged a guide 31on the engine-frame. The valve-stem 30 connects by a knuckle-joint 32with an eccentric-rod 33, driven by an eccentric 34, which is secured toa'bevel gearwheel 35, that is loose on the engine-shaft. to and carriedby the engine-shaft 3 or its main crank 8 a bevel gear-wheel 36, and thetwo bevel gear-wheels 35 and 36, one loose and the other fast on theshaft, are joined together by two bevel gear-wheels 37 and 38, that areplaced on opposite sides of the shaft and revolubly supported in areversing-lever 39, Fig. 7, provided with setscrews or studs 40, onwhich the wheels 37 and 38 are arranged to turn. The reversing-lever 39is capable of being rocked on the shaft 3 as a center and is providedwith a handle 41 and also with a somewhat-lengthened hand-rod 42, bywhich the lever can be operated from a distance. If it be supposed thatthe engine is running forward,with the reversing-valve gear in theposition as represented in Fig. 7, then it will be obvious that bydrawing the lever 39 for ward through one-quarter of a circle theeccentric 34 will be moved one-half way around or to the opposite sideof the engine shaft, thus reversing the position of the valve 29, andthereby reversing the engine.

There is cast onto the forward head of each cylinder 16, 22, and 28 acylindrical vertically-extended packing-box 43, Figs. 1, 2, and 8,through each of which is passed the piston-rod of one of theengine-pistons 15 21 or the stem of the main engine-valve 29, as thecase may be. Any suitable packing material 44 is placed in each boxaround the piston-rod or valve-stem. In one end of the packingbox is abushing 45, through which is screwed a stem 46, carrying on its innerend a follower 47 and provided at its outer end witha There is securedhand-wheel 48, whereby the follower may be screwed down onto the packing44 to tighten it around. the piston-rods and valve-stem, respectively.

It may be preferable to cast the cylinders 16 22, intermediatevalve-chamber 28, and their suitable ports all in one body, as shown inFigs. 1, 3, and 9. By reference to Figs. 1 and 9 it will be seen thatthe valve chamber or cylinder 28 is provided at one side, about midwayits length, with an inlet-port 49, through which enters a mixture of gasand air from a vaporizer 50, that is bolted to the upper side of theengine-cylinder casting. An exhaust-port 51 leads from the valve-chamber28 at a point opposite the inlet-port. This exhaust-port 51 communicateswith an exhaust chamber or T 52, inclosed in the vaporizer 50, as shownin Fig. 9, and provided with an exhaust-pipe 53, discharging into theatmosphere. The vaporizer-chamber 50 is filled with balls 54, of brass,copper, or other suitable metal or refractor T material, and these areso disposed around and in contact with the exhaust T 52 as to becomethoroughly heated by the hot exhaust-gases escaping through the said T.A perforated plate 55, Fig. 9, is secured over the port 49 to supportthe balls 54 at that point. Secured to the upper side of the vaporizer50 and communicating therewith is a gas box 56, Fig. 9, in which'is aperforated gas-pipe 57, connecting with a gas-supply pipe 58 on theoutside. At the junction of these gaspipes 57 and 58 there is agas-valve 59 to control the supply of gas to the vaporizer. Above thegas-box 56 and communicating therewith is the casing 60 of a mainair-valve 61 and sub air-valve 62, Figs. 6, 6", and 9. Both of theseareslide-valves, and each is provided with a number of rectangularopenings or perforations 63, as shown. The valves 61 and 62 are placedone on top of the other, and when the openings 63 of one valve registerwith the openings of the other valve a flow of air will be permitted topass into the gas-box 56 for mixture with the gas therein. When one orthe other valve 61 62 is moved in a proper direction, the admission ofair can be regulated as required, or the supply can be entirely cutoff.It will be seen that the main air-valve 61 is controlled by a stem 64,having a hand wheel 65 thereon and provided with a pinion 66, meshingwith a gear-wheel 67 on the stem of the gas-valve 59, so that both maybe operated together; but as it may happen that when the gas-pressure inthe pipe 58 is very high more gas than air may be admitted to the engineit is advisable to provide the independent sub air-valve 62, having stem68 and hand-wheel 69, so that more air may be admitted or its regulationcontrolled independent of the jointly-operated main air-valve andconnected gas-valve. An air-supply pipe 70 maybe connected with thecasing 60 of the double air-valve.

At the front end of the combustion-cylinextended through said box.

shown in Figs. 1, 10, and 10.

der 22 there is a diagonal port 71 to and from the valve-chamber 28, anda similar port 72 is provided at the back end of the combustion-cylinderfor communication with the corresponding portion of the valve-chamber.Like ports 7 3 and 74 are provided to establish communication betweenthe valve-chamber 28 and main engine-cylinder 16 at its front and backends, respectively. All these ports 71 to 74 are arranged diagonally, asshown in Fig. 1.

To control or shut off the ports 7 3 and 74, for a purpose hereinafterexplained, it is preferable to provide in each of said ports an ad- 3'ustable cut-off valve 75, Figs. 3 and 4:. Each valve 75 consists of astraight stem having its upper portion threaded and provided with ahand-wheel 76 on its upper end. The threaded portion of the valve screwsthrough a threaded hole in the top 77 of a casing 78, that projectsvertically from a cylindrical and horizontally placed packing box 79,through the center of which the valve 75 is passed at a right angle.This cylindrical packing-box79 is provided on its under side with athreaded boss or nipple 80, through which the valve 75 also extends. Theboss or nipple 80 is screwed into a suitable recess provided in the topof the cylinder-casting, which is also suitably cored, as at 81, Fig. 3,to provide a seat for the closed-down valve. The interior of thepacking-box 79 is screwthreaded from end to end, and in each end isreceived a screw 82, Fig. 4, provided with a wheel 83, by which thescrew can be turned to exert compression on a suitable packing material84:, that is placed in the box 79, and around the portion of the valve75, that is The valves 75 are designed to be screwed down through theports 73 and 74C to partly or entirely close them, when desired, andmore especially when it is required to accumulate power by preventingits entire expenditure in the main engine-cylinder, as hereinafterexplained. The manner of packing the straight cylindrical valves 75through the screws 82, exerting compression from both ends of thepacking-box 79 upon the packing 84 therein, provides a most reliablemeans for preventing the leakage of gas or fluid pressure around thevalve. Where convenient, this manner of securing compression from bothends of a packing-box can be applied as well to the construction shownin Fig. 8 and previously described.

The main engine-valve 29 is cylindrical, as It is provided with twogrooves 85 and 86, located longitudinally in opposite sides of itscentral portion, and it also has two longitudinally-extendedperforations or passages 87 and 88, Fig. 9, one on each side,alternating with the said grooves. A number of packing-rings 89 may beprovided on the ends of the valve. The

grooves 85 and 86 are to establish communication between the severalports of the valve- The combustion-jet, Figs. 5 and 5, for ex plodingthe gas, consistsof a cylindrical body 92, one end of which is providedwith a threaded nipple 93, by which the jet or igniter is screwed ontothe side of the oombustion-cylinder 22 at an opening 94, Figs. 1 and 9.This cylindrical body 92 constitutes a casing for a cylindrical hollowvalve 95, which is closed at its outer end and open at the inner' end.The valve 95 is provided in its periphcry with two ports 96 near theclosed valve end. alternately with a doubly-tapering tubular opening 97on one side of the igniter-body 92, one port registering at each end ofthe enginestroke. The doubly-tapering tubular opening 97 intersects thevertically-longitudinal axis of a gas-ignition chamber 98, that is atright angles with the igniter-body 92 and-in tegral therewith. Thisgas-ignition chamber 98 is threaded in both ends and has acentrally-perforated bushing 99 screwed into its lower end. Through theperforation of the bushing 99 is passed a gas-pipe 100, the upper end ofwhich constitutes a burner within the gas-ignition chamber 98, that isprovided with inlets 101 for admission of air to support combustion.There are also provided openings 102 in the contracted central portionof the doubly-tapered tube 97 at about the center of theignition-chamber 98 and directly in the flame from the gas-jet. Forimparting steadiness to the flame by improving the draft, if necessary,there may be screwed into the upper end of the ignition-chamber 98 asuitable length of pipe, as indicated by dotted lines in Fig. 5, and, asalso shownby dotted lines, there may be screwed a suitable length ofpipe into the outer screw-threaded end of the tapered tube 97 to conductaway any waste gases of combustion that may escape at each explosion ofthe combustible or explosive gas and air mixture employed in the engine.

Into the outer end of the igniter-body 92 is screwed a bushing 103, thatloosely supports a gland 104, through which is passed the stem 105 ofthe igniter-valve 95, a spring 106 being placed around the saidvalve-stem between the gland and the valve-body. stem 105 is providedwith a longitudinal groove 107, that receives the end of a setscrew 108,by which there is attached to the said gland 104 and valve-stem 105 anarm 109,

These ports 96 are adapted to register The valvewhich is concerned inimparting an oscillatory or rocking movement to the igniter orcombustion-jet valve 95, while the engagement of the set-screw 108 inthe groove 107 is such as to permit the required longitudinal movementof the valve as controlled by its spring. The valve-arm 109 connects bya rod 110, Figs. 1 and 2, with a stud 111 on the sliding cross-head 19,a slot 112 being formed in the cylindrical guide 23 for passage of saidstud. Through the movement of this crosshead 19 the valve 95 is rocked,so that one or the other of its ports 96 Will register with the tube 97of the ignition-chamber 98 at each end of the stroke of the piston 21 inthe combustion or explosion cylinder.

In order to start the engine, the gas should first be ignited as itissues from the pipe 100 into the ignition-chamber 98, Fig. 5. Byreference to Fig. 2 it will be seen that there is a gas-key 113 on thepipe 100, by which the supply of gas can be turned off and on at will.There is a similar gas-key 114 on the pipe 58, leading to the gas-box 56of the gas-and-air mixer or vaporizer 50, hereinbefore described. Asshown in Fig. 2, the gas-pipes 5S and 100 are preferably arranged asbranches of a common gas-supply pipe 115.

After igniting the gas at the pipe or burner 100 the enginebalance-wheel 4 should be revolved a few times by hand to cause asuction in the engine-cylinders and main-valve chamber 28, and thegas-valve 59 and air-valves 61 62 are opened by a proper manipulation oftheir hand-wheels 65 69, so as to give the required proportions of gasand air in the mixture to be employed for operating the engine. The airentering through pipe into the chamber 56 is there mixed with gas fromthe perforated gas-pipe 57, and from this chamber or box 56 thegas-and-air mixture passes around the exhaust-T 52 and between or amongthe balls 54 in the vaporizer 50 and so onward to the inlet-port 49 ofthe main- Valve chamber'28, Figs. 2 and 9. From this port 49 thevaporized mixture of gas and air passes into the groove 86 of the valve29, then, say, through the port 72 into the combustionclyinder 22,behind the piston 21, so that as the piston moves forward thecombustion-cylinder 22 will be filled with the gas-and-air mixture. Nowlet it be supposed that the cylinder 22 has already been filled withmixed gas and air on the front side of the piston 21 and the valve 29has just moved back as the engine passes over the center, as representedin Fig. 1. The valve 95 of the combustionjet or igniter has just openedwith one of its ports 96 in register with the tube 97, so that thegaseous mixture from the cylinder 22 Will pass through the said valveinto the said tube 97, Where it will be exploded by coming in contactwith the gas-flame in the ignitionchamber. WVhen the explosion takesplace, the valve 95 will be forced back against the spring 106; butafter the piston 21 passes the port 94, Fig. 1, the gas-pressure on thevalve 95 is relieved, and the valve will be returned by its spring,though neither valve-port 96 will again register with the tube 97 untilthe piston 21 has reached the end of its stroke. At this time the valve95 is again opened by the arm 109, actuated from the engine crosshead,and the gas will then be exploded on the rear side of the piston 21 inthe combustioncylinder. After the gas is exploded in thecombustion-cylinder 22 it passes, say, through the port 71, adjacent endof the valve-chamber 28, and port 73 to the front of the piston 15 inthe main engine-cylinder 16, Where it operates to force the said pistonback. The exploded gas, which has previously done its work in the maincylinder 16 and is behind the piston 15, passes out through the port 74into the groove of the main valve 29, then into the exhaust-port 51,andthence through the exhaust-T or chamber 52 into the exhaustpipe 53,Fig. 9, from which it escapes to the atmosphere. As the exhaust-gas isvery hot, it heats the exhaust-T 52, which in turn heats the copper orbrass balls 54 of the vaporizer 50, thus vaporizing any liquids ormoisture that may be contained in the incoming mixture of gas and airpassing among said balls to the inlet-port 49 of the main-valve chamber.This vaporizer is provided more especially for gas taken direct from oilor oil-wells and which contains a small quantity of both crude oil andgasolene.

After the engine has been in operation for a While a quantity of Watermay be turned on at a cock 116, Figs. 2 and 9, to pass through a pipe117, provided with a check-valve 118,

into the middle of the bottom side of the combustion-cylinder 22, justunder the port 94, for the combustion-jet or igniter. This Water isimmediately vaporized by the heat of the exploded gas and operates onthe engine-pistons, together with the other gas or gases, just as steamwould. Only a sufficient quantity of water is turned on at any time tokeep the engine within the limits of a proper working temperature. Thusno water-jacket is required around the engine-cylinders, and as thevapor of the water takes the place of an equal volume of exploded gas itfollows that this engine requires just that much less gas and is thatmuch more economical than the ordinary gas-engine.

By reference to Fig. 1 it will be seen that the exploded gas from theigniter-valve and combustion-cylinder 22 always enters the main-valvechamber 28 through either one of the ports 71 72 011 its way to the mainenginecylinder 16 through either one of the ports 73 74, connecting withthe'said main-valve chamber. It will also be seen that gas can pass fromeither end of the main-valve chamber 28 through the longitudinalperforations 87 S8 of the main valve.

Now it will be seen by reference to Fig. 1 that the piston 15 is aboutfour times as large as the piston 21. Therefore he the force of theexplosion in the cylinder 22 great or small it will be four times asmuch in the cylinder 16. As the pistons 15 and 21 always move inopposite directions and as the pressure of the exploded gases is alwayson the same corresponding sides of the pistons 16 and 21, it is obviousthat the exploded gases act upon the piston 21 with a retarding force ofone-fourth but by reason of the greater area of the piston 15 theexploded gases exert a working force four times as great as theretarding force, and thus drives or moves the engine as intended. Itfollows, therefore, that the engine will operate with greater or lesspower regardless of the pressure on the piston 21, and no matter howgreat the pressure on the piston 21 the force will always be three timesgreater or four times as great on the larger piston 15 by reason of itsgreater area and by reason of the direct communication between the twopistons 15 and 21 and always on the same corresponding sides. The forceof the explosion does not act upon the piston 21 to produce any power inthe engine; but the exploded gases are acted upon by the piston 21 andforced from the cylinder 22 to the cylinder 16 by reason of the greaterarea therein. It is the force exerted upon the larger piston 15 whichoperates every other part of the engine, and thus operates the smallpiston 21.

The object of the piston 21 and cylinder 22 is to act as a pump drawingin or filling with the mixed gases and then forcing the exploded gasesinto the main cylinder 16. The cylinder 22 differs from a pump, however,in that it is a complete combustion and cooling chamber, in which themixed gases are exploded and the heat therefrom reduced to a workingtemperature without any great loss of power. The explosion takes placeimmediately at the beginning of each stroke.

It will be seen that when the engine is in operation the twolongitudinal holes through the main valve 29 will be filled withexploded gases under pressure, which will be released into the'charge ofmixed gases at the end of each stroke, causing an increased pressure ofthe charge of mixed gases, forcing the same into the exploder, thuscausing an immediate explosion. These longitudinal holes in the valve 29are again refilled when the explosion takes place.

It is to be understood that the explosion does not take place on bothsides of the piston 21 at the same time, but alternately, the oppositeside of the piston 21 or theside opposite to the explosion alwaysfilling with mixed gases as the piston proceeds on its stroke. WVereboth cylinders 22 and 16 the same size, the pressure of the gases wouldbe balanced and there would be neither power nor motion produced. Themixed gases pass in through the port 49, groove 86, and port 72, Fig. 1,and fill up the space behind the piston 21 as this piston moves forwardon its stroke, and the spent or exhausted gases behind the piston 15pass out of the cylinder 16, port 74, groove 85, and exhaust-port 51, asrepresented. The exploded gases pass or are forced out of the cylinder22 by the piston 21 and pass through the port 71, through the front endof the valve-chamber 28, through the port 7 3, then in front of the mainpiston 15, driving it backward, and thus operate the engine, asrepresented. This operation is exactly repeated for the opposite strokeand by means of the corresponding opposite ports as the main valve 29 ismoved forward by the eccentric 34, and thus produces continuous motion,as represented. As the gases leave the small cylinder 22 and expand tofill the larger cylinder 16 the pressure will fall to less than one-halfand the volume will be in creased four times.

The check-valve 90 at the rear end of the main valve chamber 28 is heldnormally closed by a spring 119, Figs. 1 and 2, but can be opened, whendesired, bymeans of a hand- .lever 120, that is fulcrumed to an arm 121,

casing of the check-valve is connected 1 the bed-plate 1, as shown, andit is provided 1 with a drain-cock 125 and with a pipe or pipes 126,through which surplus or accumulated gas may be taken to operate otherengines or pumps, &c., or for use in starting this engine.

If after the engine is started it is desired to accumulate a quantity ofexploded gas to operate other engines or various machines, the portcutoff valves 75, Figs. 3 and 4, should be screwed down until theynearly close the ports 73 7 1 to and from the main engine-cylinder. Nowa greater quantity of gas and air should be turned on by the handwheel65, so thata great quantity of exploded gas will be produced inthe-combustion-cylinder 22, and then by means of the hand-lever 120 thecheck-valve 90 will be opened. The surplus gas being unableto enter themain cylinder 16 (the cutoff valves 7 5 being shut down) will pass fromboth ends of the main-valve chamber 28 through the longitudinal passages87 88' of the main valve 29, and thence through the opened check-valve90 into the accumulator and drainage cham ber 91, where, if desired, theaccumulated gas can be stored until required for use. From this chamber91 the accumulated gas may be taken by the pipe 126 to operate variousother engines, pumps, or other machines. Another object of the chamber91 is to provide for drainage of any liquids that may condense fromvapors contained in the exploded or burned gases and any solid productsof combustion which said liquids may contain in so- ICO lution, allbeing drawn oii' by the drain-cock 125 from time to time. Theaccumulator or drainage chamber 01 also affords the advantage ofmaintaining a more uniform pressure of gases for operating othermachinery, and thus has the same object as the dome on a steam-boiler.It will be obvious, also, that when this engene is at rest and there isan accumulation of gas in the chamber 91 it will be only necessary toopen the check-valve 90 in order to start the engine by back pressurefrom the accumulator.

WVhat I claim as my invention is- 1. In an engine, the combination withthe main cylinder and its piston, and a combustion-cylinder and itspiston, of a cylindrical valve-chamber intermediate the two saidengine-cylinders and provided with centrallylocated inlet and exhaustports and with ports that communicate with the ends of theengine-cylinders, and a cylindrical main valve located in the saidvalve-chamber and provided in its opposite sides with grooves to connectthe ports of the en gine-cylinders with theinlet and exhaust ports ofthe valve-chamber and having longitudinal perforations between the saidgrooves, substantially as described.

2. In an engine, the combination with the two cylinders and theirpistons, a valve-chamber intermediate the said cylinders andproexhaust-port of the said valve-chamber, metal balls or refractorymaterial placed in the vaporizer-chamber around the inclosedexhaustchamber, a gas box or chamber communicatin g with thevaporizer-chamber and provided with a perforated gas-inlet pipe, agas-valve, an air box or chamber communicating with the gas-box andprovided with an air-valve, and means for operating the gas-valve andair-valve jointly, substantially as described.

3. In an engine, the combination with the vaporizer, the gas-boxcommunicating with the vaporizer, and an air-box communicating with thesaid gas-box, of a perforated gas-inlet pipe extended into the gas-boxand provided with a gas -valve, a main air-valve geared with the saidgas-valve for joint operation,and an independently-operated subairvalve, substantially as described.

t. In an engine, the combination with a main cylinder and its piston anda combus tion-cylinder and its piston, and means for supplying saidcombustion-cylinder with an explosive gas, of an igniter orcombustion-jet composed of a valve-ch amber and an ignitionchamber, thesaid valve-chamber being intermediate the combustion-cylinder and saidignition-chamber and having a perforated tubular passage extendedthrough the ignition-chamber, means for maintaining a flame in the saidignition-chamber around the said tubular passage, and a valve located inthe said valve-chamber of the igniter and actuated from a moving part ofthe engine, substantially as described.

5. In an engine, the combination with a main cylinder and its piston anda combustion-cylinder and its piston, and means for supplying the saidcombustion-cylinder with an explosive gas, of an igniter orcombustionjet provided with a valve actuated from a moving part of theengine and adapted to control an explosion of gas in thecombustioncylinder at the end of each stroke, substantially asdescribed.

6. In an engine, the combination with the main engine-cylinder and itspiston, a combustion-cylinderandits piston, a valve-chamber intermediateand communicating with said cylinders, and a main engine-valve locatedin said chamber, and provided with longitudinal passages, of anaccumulatorchamber provided with a drainage-cock, a check-valveintermediate the main-valve chamber and said accumulator, cut-off valvesfor the ports between the main-engine-valve chamber and mainengine-cylinder, and a pipe leading from the accumulator-chamber,

substantially as described.

7. In an engine, the combination with the main engine-cylinder and itspiston, the combustion-cylinder and its piston, the main-engine-valvechamber having ports communicating with the engine-cylinders and thelongitudinally-perforated main engine-valve located in said chamber, ofthe cut-oft valves in the ports between the main engine-cylinder andmain-valve chamber, an accumulator-chamber adapted to communicate withthe main-valve chamber and provided with an outlet-pipe for conductingaccumulated pressure to another engine or machine, and a valve tocontrol communication between the main-valve chamber and saidaccumulator-chamber, substantially as described.

8. In an engine, the combination with the main engine-cylinder and itspiston, the mainvalve chamber having ports communicating with said maincylinder, and an accumulatorchamber communicating with the saidmainvalve chamber, of cut-01f valves for the ports between themain-valve chamber and main cylinder, each of said cut-oft valvesconsisting of a straight cylindrical body screwthreaded at one end andsupported in a packing-box with which the threaded portion of the valveis engaged, a hand-Wheel for said valve, and screw-threaded followersfor compressing the packing around said valves, sub stantially asdescribed.

9. In an engine, the combination of the enginecylinders and theirpistons, a crankshaft with which the piston-rods are connected, a mainengine-valve intermediate the two engine-cylinders and actuated from aneccentric on the main shaft, a reversing-gear I for said valve,mechanism for exploding gas in one of the engine-cylinders, and anaccumulator for gas-pressure adapted to have- I11 testimony whereof Ihave hereunto set my hand in presence of two subscribing wit- 1o nesses.

ALLEN H. DINGMAN.

Witnesses:

SEBASTIAN A. HEISEL, WILLIAM B. GooHRAN.

